The invention relates to a device for producing clutch bodies, which are suitable for synchronizer systems and provided with teeth or tooth sections (both of which my be referred to simply as “teeth”), from a blank using at least one embossing stage, composed of embossing segments and an anvil, for embossing roofs and troughs between the root and tip circles into an upper face of the blank, and transfer means for transporting the blanks.
The invention further relates to a method for producing clutch bodies, which are suitable for synchronizer systems, from a blank using an embossing stage, which comprises at least embossing segments and an anvil and in which troughs and roofs in the edge region close to the circumference arranged next to each other in a ring-like manner are introduced into the upper face of the blank by way of embossing along a root circle and tip circle of the future teeth or tooth sections.
A method for producing stamped parts, in particular synchronizer rings, clutch bodies or clutch plates, is known from EP 2 263 812 A1 in which, in one method step, the strip stock to be worked is clamped between the hold-down elements of a fine blanking tool, and in a further method step at least the teeth are embossed. In a first process step, an impact pre-embossing step is carried out on the strip stock at least in the region of the teeth that are to be cut out later, and subsequently the fine blanking method step is carried out in conjunction with an impact extrusion step on the strip stock. The teeth are formed by way of a fine blanking operation and subjected to impact extrusion at the same time, during which they are displaced into a free volume created by way of pre-embossing.
Impact pre-embossing, which is nothing other than embossing, forces a change in the shape of the strip stock, preserving the cohesion and volume of the material.
This is associated with the disadvantage that stresses or compressions are created in the embossing region of the strip stock as a result of the changes in shape and geometry, which can impair the flatness of the strip to be cut and the dimensional accuracy of the future teeth.
Moreover, DE 2 222 080 A1 describes a method and a die for producing clutch bodies for synchromesh gears comprising teeth, which have a tooth profile having roof-like axial displacement surfaces on the flank side and stepped head surfaces on the end face side, forming stop lugs, for engaging an associated selector sleeve. The teeth are initially fine blanked, and then the tooth profile is embossed. For this purpose, the stamped teeth are in each case pre-embossed in a die comprising a hollow mold corresponding to the tooth profile and subsequently, with the die closed, finished by way of a displacement punch that is moved into the hollow mold, filling the hollow mold.
This known method is very complex since the teeth must be fed consecutively to the die, or each tooth must be assigned a dedicated die. In addition, the teeth must be stamped in an undersized dimension, so that flawless filling of the hollow mold is achieved with the required fine dimension.